The use of radio frequency current to cut and cauterize human tissue in surgical procedures was developed by W. T. Bovie and Harvey, Surg. Gyn. and Obs., 47:751-84 (1928). This technique is well known and commonly employed today in many different types of operations.
In endoscopic surgical procedures, an instrument is inserted through a narrow opening made in the body, or through an available natural orifice, such as the throat, rectum or urethra. This instrument contains an integrally illuminated telescope which is used to provide the surgeon with a view of the tissue under consideration. In addition to the telescope, endoscopic instruments usually have working channels to admit one of several different implements: grasping forceps, punches, and electric cutting loops. Of particular interest to this invention is the resectoscope commonly used in urology to remove the prostate and bladder tumors. This instrument is also used in gynecology to remove fibroids of the ureterus as well as to perform percutaneous hysterectomies.
The resectocope is enveloped by a sheath, which is first introduced into the body of the patient. The working implements are then passed through the sheath whose sole function is to act as a conduit of safe passage to the targeted tissue. The working implements are usually joined together into one appliance consisting of: (1) a channel for the telescope, (2) a channel for the electric wire loop and (3) a channel to permit the flow of fluid out of the patient. The space within the sheath not occupied by the appliance is used to provide a passageway for the flow of irrigating fluid into the patient at the surgical site.
Although provision has been made to permit egress of fluid, and thereby to regulate the pressure exerted by the irrigating fluid upon the patient's tissues, the outflow channel can not accommodate the passage of dissected tissue. In procedures in which the resectoscope is used, cut tissue is flushed from the site by the irrigation flow to adjacent open voids, such as the bladder, and later removed using a suction/irrigator, or by simply washing the dissected fragments out of the body using copious irrigation, through the original opening used or made to reach the tissue.
If tissue could be aspirated as it is dissected, several beneficial results would be obtained:
1. Enhanced visibility of the dissection site; PA0 2. A shortened operative time; and PA0 3. The ability to biopsy selected tissue sites. PA0 1. Electrical cutting can be used to dissect tissue found resistant to ultrasonic attack as, for example, connective tissue of low water content interlacing a tumor or benign growth whose entire removal is sought; PA0 2. Ultrasonic cutting can be employed on tissue near sensitive structures, such as the bladder neck and prostatic capsule, whose removal is never intended, that are resistant to the ultrasonic technique but easily dissected electro-surgically; PA0 3. The simultaneous application of ultrasonic vibration and coagulating current to dissect and seal bleeding tissue; and PA0 4. The use of a laser allows the tissue to be fulgerated: i.e., unwanted cells are destroyed while bleeding of adjacent tissue is stopped.